Injection molding is a processing technology widely used in the manufacturing industry. It refers to the process of injecting molten plastic into a mold through high pressure, and then cooling and forming. Injection molding has the advantages of high efficiency, high precision, and low cost, so it has been widely used in the fields of automobiles, electronics, medical treatment, toys, and so on. This article will introduce the basic principles and processes of injection molding.
1. The basic principle of injection molding
The basic principle of injection molding is to melt plastic particles by heating and high pressure, then inject the melted plastic into the mold through a syringe, and finally cool and form. The basic principle of injection molding processing can be divided into the following steps:
1. Feeding: Add plastic pellets into the hopper of the injection molding machine.
2. Melting: The plastic particles are melted by heating and high pressure, usually needing to raise the temperature above 150°C.
3. Injection: The molten plastic is injected into the mold through a syringe, and the injection pressure usually needs to be controlled between 1000-2000 bar.
4. Cooling: To cool the plastic injected into the mold, it is usually necessary to lower the mold temperature below 50°C.
5. Take out: Take the formed product out of the mold.
Second, the process of injection molding
The injection molding process can be divided into the following steps:
1. Mold Design: Design the mold according to the shape and size of the product.
2. Material preparation: Select plastic pellets suitable for the product and add them to the hopper of the injection molding machine.
3. Heating and melting: Heat the heater in the injection molding machine to an appropriate temperature to melt the plastic pellets.
4. Injection: Inject molten plastic into the mold through a syringe, usually requiring control of injection pressure and speed.
5. Cooling: To cool the plastic injected into the mold, it is usually necessary to control the temperature and cooling time of the mold.
6. Take out: take out the formed product from the mold, and carry out subsequent processing, such as removing the support structure, grinding, etc.
7. Inspection and packaging: inspect the formed products, such as size, appearance, etc., and then pack them.
3. Matters needing attention in injection molding
1. Select plastic pellets suitable for the product. Different plastic pellets have different characteristics, such as hardness, strength, heat resistance, etc.
2. Control the injection pressure and speed, too high injection pressure and speed will cause the product to deform or break.
3. Control the mold temperature and cooling time, different products require different temperatures and cooling times.
4. Inspect the formed products, such as size, appearance, etc., to ensure that the products meet the requirements.
5. Pack to avoid product damage during transportation and storage.
4. the application of injection molding
Injection molding is widely used in the manufacturing industry, mainly in the following fields:
1. Automobile manufacturing: auto parts, lights, instrument panels, etc.
2. Electronic manufacturing: mobile phone casing, TV casing, computer casing, etc.
3. Medical equipment: syringes, infusion sets, sphygmomanometers, etc.
4. Toy manufacturing: plastic toys, child seats, etc.
5. Household items: plastic chairs, plastic barrels, etc.
In short, injection molding is a high-efficiency, high-precision, and low-cost processing technology, which is widely used in the manufacturing industry. By understanding the basic principles and processes of injection molding, we can better understand this processing technology and better master it in practical applications.